I think replacing parts is a good idea, but comes up against some harder limits... Surgery becomes harder to recover from as you get older. Cell division limits

I think replacing parts is a good idea, but comes up against some harder limits... Surgery becomes harder to recover from as you get older. Cell division limits are a thing, build-up of scarring tissue, etc. So if we can address cellular aging mechanisms, I think we'll have the latitude to address some of the more macroscopic aging problems (like joints, etc) through surgery.